Abstract: A process for impregnating an electrical coil which comprises a winding comprising two or more layers consisting of more than one turn of an electrically conducting wire-form material with a polymer material which electrically insulates the individual turns of the wire-form material from one another with the aid of a thermally curable epoxy resin composition, which composition is solid at room temperature and comprises the following constituents: (a) an epoxy resin which is solid at room temperature, selected from (a1) polyglycidyl ethers based on novolaks; (a2) diglycidyl ethers based on bisphenols, and (a3) mixtures of more than one of components (a1) and (a2); (b) a crosslinking agent for component (a); (c) a suitable accelerator for the reaction of component (a) and component (b); (d) from 15 to 70 percent by weight, based on the overall weight of the composition, of filler selected from (d1) calcium carbonate, (d2) quartz flour, (d3) wollastonite whose particles have an average ratio of length

Abstract: A process for impregnating an electrical coil which comprises a winding comprising two or more layers consisting of more than one turn of an electrically conducting wire-form material with a polymer material which electrically insulates the individual turns of the wire-form material from one another with the aid of a thermally curable epoxy resin composition, which composition is solid at room temperature and comprises the following constituents:(a) an epoxy resin which is solid at room temperature, selected from(a1) polyglycidyl ethers based on novolaks;(a2) diglycidyl ethers based on bisphenols, and(a3) mixtures of more than one of components (a1) and (a2);(b) a crosslinking agent for component (a);(c) a suitable accelerator for the reaction of component (a) and component (b);(d) from 15 to 70 percent by weight, based on the overall weight of the composition, of filler selected from(d1) calcium carbonate,(d2) quartz flour,(d3) wollastonite whose particles have an average ratio of length to cross-section whi

Abstract: Two flanges form together with an outer tube a sealed-off casting mold for applying an envelope to a pipe at least part of which is lodged in the mold. The lower flange is equipped with a feed-in duct system and the upper flange with an air-escape and overflow duct. The flanges consist of a material of rubber-like elasticity.The duct system of the lower flange comprises a radially extending bore which opens in an annular distributory channel which merges with aerodynamic contours with a flow gap. The flow gap is of such configuration that it is closed when, and as long as, a higher pressure is exerted on the forward frontal face of the lower flange than prevails in the annular channel.The flanges are so shaped in the regions of their sealing faces that the contact pressure exerted on them increases proportionally with the pressure exerted on one of the frontal faces.